1. Field of Invention
The present invention relates to a derailleur of bicycles, and more particularly, to an electronic rear derailleur of bicycles, which can prevent from a jam or an unstable drive problem.
2. Related Art
Currently, most of modern bicycles have a variable-speed function through a rear derailleur installed on bicycles. Through the rear derailleur, the bicycle chain can be shifted from a present sprocket to a target sprocket of the rear sprockets, so as to achieve the variable-speed function. In addition, due to the advancement of bicycle industry, the rear derailleur has been developed to an electronic derailleur driven by an electric motor. In this configuration, a bicycle shifter installed on the handlebar of the bicycle is used to control the activation of the electric motor. When receiving a signal to activate, the electric motor will drive gear sets to drive the derailleur, so that the chain of the bicycle can be shifted to a predetermined sprocket to achieve the variable-speed function.
However, the bicycle may be vibrated when driving in road, so that the components of the derailleur may be also vibrated, which may lead to misalignment or jam between the gear sets. Especially, when the derailleur is suffered an impact, the impact may not only cause the misalignment or jam of the gear sets, but damage the electric motor, which leads to the problem of inaccurate speed change or even need to replace a new electric motor.